diff --git a/SAS/TMSS/backend/src/Dockerfile-tmss b/SAS/TMSS/backend/src/Dockerfile-tmss
index 4a7d2dddc01c0d8a4a773567af87fdff6ee4c022..25dcf810a99b010e90d1e6bf3a2f9f11700915b9 100644
--- a/SAS/TMSS/backend/src/Dockerfile-tmss
+++ b/SAS/TMSS/backend/src/Dockerfile-tmss
@@ -7,9 +7,9 @@
 #
 # docker build [-t image_name:tag] -f docker/Dockerfile-tmss .
 #
+FROM ci_scu:$TMSS_VERSION
 ARG TMSS_VERSION=latest
 ARG TMSS_COPY_DIR="./installed"
-FROM ci_scu:$TMSS_VERSION
 
 USER lofarsys
 RUN mkdir -p /opt/lofar
@@ -19,8 +19,9 @@ WORKDIR /opt/lofar
 
 ENV LOFARROOT=/opt/lofar
 
+RUN echo "Copy from $TMSS_COPY_DIR"
 # Add the rest of the code
-COPY --chown=lofarsys:lofarsys $TMSS_COPY_DIR /opt/lofar
+COPY --chown=lofarsys:lofarsys ${TMSS_COPY_DIR} /opt/lofar
 
 # docker only chowns the copied dir, not the full tree
 RUN chown -R lofarsys:lofarsys /opt/lofar